On relation of the long period galactic cosmic rays intensity variations with the interplanetary magnetic field turbulence

Alania, M. V.; Iskra, K.; Siłuszyk, Marek

doi:10.1016/j.asr.2010.01.020

Cited by 21 publications

(23 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To provide at least an acceptable accuracy for the calculated value of γ we used carefully selected appropriate NMs for each chosen period of solar activity. Siluszyk (2009, 2010) calculated the annual average values of ν y and ν z by the method given in Appendix B. This method (which we call the first method) assumes the same frequency interval f = f 2 − f 1 = 3 × 10 −6 Hz and constant resonant frequencies Table 1 Neutron monitors used to calculate γ , denoted by '+' in the analysis periods.…”

Section: Observational Data and Analysis Methodsmentioning

confidence: 99%

“…The top panel shows the GCR intensity variations J from Moscow neutron monitor data rescaled to free space using the coupling coefficients by Yasue et al (1982) and Alania, Iskra, and Siluszyk (2010). In the entire period of 1968 -2002, there exists a clear negative correlation between J and γ (correlation coefficient r = −0.62 ± 0.12) and a positive correlation between SSN and γ (r = 0.70 ± 0.11), in spite of some time delays between the peaks and valleys in J , SSN, and γ of individual 11-year cycles.…”

mentioning

confidence: 99%

“…The scattering of GCR particles in the heliosphere is generally caused by the turbulence of the B y and B z components of the IMF (Jokipii, 1971;Bieber, Mathaeus, and Smith, 1994), although the roles of the two components are not equal at all. The average power of the PSD of the B y component (∼ f ν y ) is more than twice as large as the average power of the B z component (∼ f ν z ).…”

mentioning

confidence: 99%

“…It is shown that, in the first approximation, about 75 -80 % of the 11-year variation of the GCR intensity can be interpreted based on the anisotropic diffusion-convection model of GCR propagation (Dorman, 2001;Alania, 2002;Alania, Iskra, and Siluszyk, 2010;Strauss and Potgieter, 2014) for particles of rigidity range 5 -35 GV that are detected by neutron monitors (NMs). According to the quasi-linear theory (QLT) by Jokipii (1971) and Shalchi (2009), there should be a relationship between the parallel diffusion coefficient K // and rigidity R of GCR particles, as K // ∝ R α for the rigidity range of NMs.…”

mentioning

confidence: 99%

“…We have calculated the annual average values of ν y and ν z (Alania, Iskra, and Siluszyk 2008a, 2008b, 2010 for the period 1968 -2002 and divided them into three subperiods -I: 1968-1976, II: 1977-1989, and III: 1990-2002. Period I corresponds to the second half of solar cycle 20.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Rigidity Dependence of the Long-Term Variations of Galactic Cosmic-Ray Intensity in Relation to the Interplanetary Magnetic-Field Turbulence: 1968 – 2002

2014

Self Cite

View full text Add to dashboard Cite

We studied the relationship between the power-law exponent γ on the rigidity R of the spectrum of galactic cosmic-ray (GCR) intensity variation (δD(R)/D(R) ∝ R −γ ) and the exponents ν y and ν z of the power spectral density (PSD) of the B y and B z components of the interplanetary magnetic field (IMF) turbulence (PSD ∼ f −ν , where f is the frequency). We used the data from neutron monitors and IMF for the period of 1968 -2002. The exponents ν y and ν z were calculated in the frequency interval f = f 2 − f 1 = 3 × 10 −6 Hz of the resonant frequencies (f 1 = 1 × 10 −6 Hz, f 2 = 4 × 10 −6 Hz) that are responsible for the scattering of GCR particles with the rigidity range detected by neutron monitors. We found clear inverse correlations between γ and ν y or ν z when the time variations of the resonant frequencies were derived from in situ measurements of the solar wind velocity U sw and IMF strength B during 1968 -2002. We argue that these inverse relations are a fundamental feature in the GCR modulation that is not restricted to the analyzed years of 1968 -2002.

show abstract

Section: Observational Data and Analysis Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Rigidity Dependence of the Long-Term Variations of Galactic Cosmic-Ray Intensity in Relation to the Interplanetary Magnetic-Field Turbulence: 1968 – 2002

2014

Self Cite

View full text Add to dashboard Cite

show abstract

Peculiarities of cosmic ray modulation in the solar minimum 23/24

2014

View full text Add to dashboard Cite

We study changes of the galactic cosmic ray (GCR) intensity for the ending period of the solar cycle 23 and the beginning of the solar cycle 24 using neutron monitors experimental data. We show that an increase of the GCR intensity in 2009 is generally related with decrease of the solar wind velocity U, the strength B of the interplanetary magnetic field (IMF), and the drift in negative (A < 0) polarity epoch. We present that temporal changes of rigidity dependence of the GCR intensity variation, before reaching maximum level in 2009 and after it, do not noticeably differ from each other. The rigidity spectrum of the GCR intensity variations calculated based on neutron monitors data (for rigidities > 10 GV) is hard in the minimum and near-minimum epoch. We do not recognize any nonordinary changes in the physical mechanism of modulation of the GCR intensity in the rigidity range of GCR particles to which neutron monitors respond. We compose 2-D nonstationary model of transport equation to describe variations of the GCR intensity for 1996-2012 including the A > 0 (1996-2001) and the A < 0 (2002-2012) periods; diffusion coefficient of cosmic rays for rigidity 10-15 GV is increased by~30% in 2009 (A < 0) comparing with 1996 (A > 0). We believe that the proposed model is relatively realistic, and obtained results are satisfactorily compatible with neutron monitors data.

show abstract

Interplanetary Magnetic Field Turbulence and Rigidity Spectrum of the Galactic Cosmic Rays Intensity Variation (1969–2011)

et al. 2018

Self Cite

View full text Add to dashboard Cite

The present study investigates the relation between the rigidity R spectrum exponent γ of the galactic cosmic rays (GCR) flux changes (δD(R)/D(R) ∝ R−γ) and the exponents νy and νz of the power spectral density of the By and Bz components of the heliospheric magnetic field (HMF) fluctuations. Two parameters have been introduced: (1) the exponent γ demonstrating the rigidity dependence of long‐term changes of GCR flux on solar activity (SA) and (2) the exponents νy and νz signifying the state of turbulence which is divided of the By and Bz components. This study considers the period of time between 1969 and 2011 divided into four subperiods, according to the solar global magnetic field polarities: (I) 1969–1979, (A > 0) (positive polarity magnetic field lines are directed away from the Sun's northern hemisphere); (II) 1980–1988, (A < 0) (negative polarity magnetic field lines are directed toward the Sun's northern hemisphere); (III) 1991–2001, (A > 0); and (IV) 2002–2011, (A < 0). The paper finds that temporal changes of the resonant frequency (fres) of GCR protons in heliospheric magnetic field turbulence in relation to SA are mainly caused by variations of the induction of B components from year to year, while the contribution of the solar wind speed remains insignificant. The analyses of the four subperiods show that γ increases and νy and νz decrease in the periods of increased SA, and conversely, the γ decreases and νy and νz increase in the periods of reduced SA. The study concludes that the exponents γ, and νy and νz can be considered as important indices (proxies) for research on GCR transport in the heliosphere.

show abstract

On relation of the long period galactic cosmic rays intensity variations with the interplanetary magnetic field turbulence

Cited by 21 publications

References 35 publications

Rigidity Dependence of the Long-Term Variations of Galactic Cosmic-Ray Intensity in Relation to the Interplanetary Magnetic-Field Turbulence: 1968 – 2002

Rigidity Dependence of the Long-Term Variations of Galactic Cosmic-Ray Intensity in Relation to the Interplanetary Magnetic-Field Turbulence: 1968 – 2002

Peculiarities of cosmic ray modulation in the solar minimum 23/24

Interplanetary Magnetic Field Turbulence and Rigidity Spectrum of the Galactic Cosmic Rays Intensity Variation (1969–2011)

Contact Info

Product

Resources

About